The histology and stereology support core was created to maximize the use of available resources for[unreadable] mouse brain tissue processing, paraffin or cryo- embedding, serial sectioning and histological staining of[unreadable] sections for stereology and collaborative studies involving Projects 1, 2, 3 and 4. Core B also provides[unreadable] equipment, supplies and expertise required for the processing, embedding, sectioning and histological[unreadable] staining of brain tissue from patients ascertained through the Director and clinical collaborators. The goals of[unreadable] Core B include:[unreadable] 1. Preparation of tissue and standardization of stereological methods in adult and postnatal brain of[unreadable] genetic mouse models. For all models in the PPG the core will produce material facilitating the direct[unreadable] comparison of mouse strains using highly standardized histological and quantitative anatomical methods.[unreadable] 2. Whole-brain phenotyping of models. Brains will be paraffin-embedded at key postnatal ages for[unreadable] phenotyping with histochemical (H&E/NissI) and immunological stains. Data will include sizes of major[unreadable] nuclei; total cell number and pathological cell profiles. Projection neuron representation will be assessed[unreadable] by cell morphology and immunohistochemistry (IHC).[unreadable] 3. Archiving brains of behaviorally characterized mice. The time and resources invested in behavioral[unreadable] testing makes it cost effective to paraffin embed and archive all brains from behavioral studies. These[unreadable] tissues can be used to confirm an anatomical effect in the same cohort or test posf hoc hypotheses[unreadable] related to known behavioral phenotypes.[unreadable] 4. Archiving embryos (some BrdU pulse-labeled) of multiple genotypes at a range of gestational ages.[unreadable] Extra embryos generated by Projects 1,2 & 3 experiments will be processed, paraffin embedded and[unreadable] archived to be available for later investigation of new questions and hypotheses as the work progresses.[unreadable] 5. Correlative human brain pathology. While rodent models suggest that human disorders affecting[unreadable] primarily interneurons are likely, human data are mostly lacking. Core B will process tissue blocks or fixed[unreadable] tissues ascertained through the Director and clinical collaborators. Slides prepared for histochemistry and[unreadable] IHC in Core B will be analyzed by Project 1 and 2 investigators.[unreadable] 6. Mouse inventory and identification. Although each project will maintain its own mouse lines, Core B,[unreadable] will periodically update the nomenclature and inventory of genetic models available through the PPG and[unreadable] facilitate coordination across projects in order to procure and facilitate initial analysis of useful lines and[unreadable] crosses.